For devices, especially in medical environment, it is essential to know the condition of the device and if any lids, covers, or similar are open. Communication devices used in medical environments generally comprises multiple lids that are opened and closed for different tasks. One example is when the device needs to be charged and the user thereby is required to connect the device to a power source, another is when a memory card, SIM card, or any other form of input media is entered into the device. The lids are important for water resistance properties and in order to eliminate the risk of sparks. For example, in some areas where gases are handled it is dangerous if a mobile device is not enclosed in a way preventing sparks from coming into contact with the environment outside the casing of the device. It is further essential for the function of the communication in such an environment that the communication devices still can safely be used.
In prior art it is known to arrange micro switches in order to indicate if for example a lid is open and to prevent the user from using a device that isn't properly assembled or configured. Preventing the user can be either through presenting warnings on a display or in some embodiments to disable the entire communication device. One way of ensuring this is for example to present the user with an alarm if a lid of the device is open. Ensuring that all lids are closed is important for many different reasons, for example in order to maintain water resistance and reduce the risk of contamination. It is further beneficial to ensure that all lids are closed in order to reduce the risk of the lids being damaged during normal use, especially if the device is a mobile device.
The prior art solutions have further drawbacks when for example ensuring that a device is water resistant. A mechanical switch is actuated by a small section of the lid and in reality only indicates that the particular section is closed. If the lid is damaged or broken it might not fulfill its purpose although the switch indicates that it is properly in place. There are no means for indicating if the lid is arranged in a faulty way and thereby may compromise the water resistance of the communication device even if the switch indicates that the lid is closed.
In prior art it is further known to arrange other types of sensors, such as acoustic or light sensors in order to detect if a lid is opened or closed. The acoustic solutions generally comprises a sensor and a speaker. The sensor is a microphone arranged at the lid or device opposite to the speaker and then evaluates if the device lid is opened or closed through measuring the volume of an acoustic signal. There are many drawbacks with this solution, especially in relation to the need of a sensor in the lid. Thereby, this solution has mostly been utilized for folding telephones wherein the lid for example is the keyboard or another solid structure already comprising electronic components.